NEW YORK (AP) — At Columbia University and elsewhere, the fear among students that the New York Police Department might secretly be infiltrating their lives has spread beyond the Muslim student population to others who find the reported tactics “disgusting,” as one teenager put it.

The NYPD surveillance of Muslims on a dozen college campuses in the Northeast is a surprising and disappointing violation, students said Saturday in reaction to Associated Press reports that revealed the intelligence-gathering at Columbia and elsewhere.

“If this is happening to innocent Muslim students, who’s next?” asked freshman Dina Morris, 18, of Amherst, Mass. “I’m the child of an immigrant, and I was just blown away by the news; it’s disgusting.”

Documents obtained by the AP show the NYPD used undercover officers and informants to infiltrate Muslim student groups. An officer even went whitewater rafting with students and reported on how many times they prayed and what they discussed. Police also trawled college websites and blogs, compiling daily reports on the activities of Muslim students and academics.

It was all part of the NYPD’s efforts to keep tabs on Muslims throughout the region as part of the department’s anti-terrorism efforts. Police built databases of where Muslims lived and worked, where they prayed, even where they watched sports.

In the past week, Muslims and non-Muslims alike held a town hall meeting on the Manhattan campus of the Ivy League college to discuss the police surveillance. Concerned members of many school groups attended.

On Friday, some of their counterparts at New York University choked up as they gathered to voice their outrage at the notion that even students’ religious habits were being tracked by the NYPD.

“Why is the number of times that we pray per day — whether or not I come in this space and put my forehead on the floor in worship of my Lord — why does that have anything to do with somebody trying to keep this country safe?” said Elizabeth Dann, 29, an NYU law student.

At first, when it was revealed last weekend that Muslim students were targets of police surveillance, “people were distressed and frazzled,” Mona Abdullah, a member of Columbia’s Muslim Students Association, told the AP.

But by Saturday, she said, a different mood descended on the campus.

“We’re now feeling a sense of unity, because this is not an issue that affects only Muslims,” Abdullah said. “We’re still worried, but there’s also a sense of solidarity over an issue that has to be taken seriously by everyone.”

Students are also feeling empathy for those outside the university community who are being subjected to the NYPD’s “stop-and-frisk” policy targeting anyone who seems suspicious, mainly blacks and Hispanics.

“We’re not the first and we’re definitely not going to be the last,” Abdullah said.

Police were interested in Muslim student groups because they attracted young men, a demographic that terrorist groups have tapped. The NYPD defended the effort, citing a dozen accused or convicted terrorists worldwide who had once been affiliated with Muslim student groups.

But students say that unfairly categorizes them all as potential terrorists.

The Muslim students “are just as American as anyone, and to make them feel unsafe and unwanted is really unfair!” said Morris, who attends Barnard College, which is affiliated with Columbia.

“There was a lot of police blowback after 9/11; they were not respecting civil liberties,” said Leo Schwartz, 19, a political science major and columnist for Columbia’s student newspaper, the Daily Spectator.

Anmol Gupta, 22, an engineering student, said that in a city like New York, which prides itself on ethnic diversity, “the idea of the surveillance of Muslims does surprise me, it’s disturbing.”

Sitting on a bench, he glanced across the university’s quad at the students of many races and faiths who were walking around on a chilly winter day.

Gupta said he didn’t feel students could do anything to stop the surveillance.

They certainly shouldn’t do anything to change how they live from day to day — even if they’re afraid they’re being watched, Abdullah said. “We’re saying, ‘Don’t change the way you act, don’t change anything you do, because we’re not doing anything wrong.”’

Still, many on the campus of more than 25,000 students craved reassurance.

University President Lee Bollinger plans to host a fireside chat on Monday evening to discuss the secret monitoring.

He said in a statement Friday: “We should all be able to appreciate the deeply personal concerns of the Muslim members of our community in learning that their activities were being monitored — and the chilling effect such governmental efforts have on any of us in a university devoted to the foundational values of free speech and association.”

On Saturday, the unanswered question among Columbia students remained: Is the NYPD still conducting surveillance on students?

Police Commissioner Raymond Kelly said Friday: “We’re going to continue to do what we have to do to protect the city.”

He did not elaborate.

And Mayor Michael Bloomberg said his police department’s monitoring of Muslims — even outside the city at colleges in Connecticut, New Jersey, Pennsylvania and upstate New York — was “legal,” “appropriate” and “constitutional.”

Authorities left open what students most wanted answered — “if and when the surveillance ended,” Abdullah said.